Treating web-like material by a gaseous medium



Dec. 12, 1961 c. ALLANDER ETAL TREATING WEB-LIKE MATERIAL BY A GASEOUS MEDIUM Filed Nov. 7, 1958 2 Sheets-Sheet 1 o o o o .o o o o o o o o o o o v o o o o o o o Q o o o. o o o o o o o o o v o o o o o o o o o o o z o o o o o o o o o o o e o o o o o o o o o o o o o o o O O O O O O O O 0%0 O E.. E..

o o o o o o INVENTORSI CLAES ALLANDER SVEN WALLIN Dec. 12, 1961 c. ALLANDER ETAL 3,012335 TREATING WEB-LIKE MATERIAL BY A GASEOUS MEDIUM Filed NOV. 7, 1958 2 Sheets-Sheet 2 um nn MW |NvENToRs= CLAI-:s ALLANDER svEN WALLIN HJALTE PETERssoN TTYS.

United States Patent 3,012,335 TREATING WEB-LIKE MATERIAL BY A GASEOUS MEDIUM Claes Allander, Sodra Angby, Sven Wallin, .Ionkoping, and Hjalte Petersson, Kortebo, Sweden, assignors to Aktiebolaget Svenska Flaktfabriken, Stockholm, Sweden Filed Nov. 7, 1958, Ser. No. 772,529 Claims priority, application Sweden Nov. 16, 1957 2 Claims. (Cl. 34-155) The present invention relates to a method and apparatus for drying or similar treatment of a web-like material by means of a gaseous treating medium, which is supplied to the web in form of jets caused to impinge substantially perpendicularly against the surface of said web. As a method the invention is characterized in that the jets are formed with a small diameter and are uniformly distributed over the entire surface of the web to be treated and that the supplied 'creating medium is discharged from the web at a number of exhaustion points uniformly distributed in the same manner and situated between said medium jets so that the medium, when discharged, is caused to flow along the web from all directions radially towards said exhaustion points.

In accordance with the invention idea, the supplied medium can, across the web, be divided into a number of mutually adjustable currents.

The apparatus according to the invention consists of a manifold or distributing box for a gaseous medium having a wall facing the web and arranged parallel to same, said wall being equipped with apertures for supplying the treating medium, said box being connected to one or more means for supplying and conditioning the treating medium. The invented apparatus is characterized in that the wall of the distributing box facing the web is provided with a great number of apertures for the supply of the treating medium against the Web, said apertures having a small diarneter and being uniformly distributed over the entire wall surface. The wall furthermore is provided with a small number of openings with a great diameter for the discharge of the medium, said openings being arranged between said supply apertures and in the same marmer uniformly distributed over the entire wall surface. Preferably the discharge openings are connected to the suction side of the supply means or to the atmosphere by means of pipes passing through said distributing box.

As stated above, it is an essential characteristic of the invention that the treating medium, which is caused to impinge against the Web in form of fine jets, is radially conducted towards the exhaustion points from all directions instead of as hitherto in only one direction towards exhaustion slots disposed across the web, or one or more rows of openings forming together such a slot for the discharge of the medium. According to the invention the supply apertures as well as the discharge openings are uniformly distributed over the entire surface of the web to be treated. This results in that the supply of the medium is uninterrupted along the whole length of the treatment passage way and is more uniform than hitherto has been possible. At the same time a very high a-value or coefficient of heat-transmission can be maintained during the treatment because Vall the medium jets reach the web without being disturbed by the medium flowing towards the discharge slots as hitherto. The invention will also result in a very low resistance in the circulation circuit of the gaseous medium. From construction view-points the invented arrangement involves the feature that the fans as well as the heating elementsdue to the fact that the discharge pipes pass through the distributing boxeseasily can be mounted in direct connection with the distributing boxes. Although not limited to the treatment of material on drying cylinders, the invention can for reasons men- 3,0l2,335 Patented Dec. 12, 1961 tioned above be used in such driers, so called Yankee machines. Because it is possible to provide a compact design of the apparatus, the invention involves the feature that a very great quantity of circulating treating medium can be used without increasing the running costs. In drying for instance, said feature in tum Will result in a very high evaporation per square unit of the Web.

When the treating medium is supplied as a number of separate currents across the treating apparatus said apparatus can for the adjustment of said currents be equipped with a number of adjustable dampers arrangedy between the means for the medium supply and the apertures of the distributing box. By arranging the dampers in front of the fans it will be possible to prevent a too heavy supply of the medium in front of the fans, which otherwise would give an uneven treatment.

The invention will now be described. more in detail With reference to the accompanying drawings, in which FIG. 1 shows a vertical cross-section through an exemplifying embodiment of an apparatus according to the invention;

FIG. 2 shows an enlarged horizontal cross-section along the line 2-2 in FIG. 1;

FIG. 3 is an enlarged vertical cross section along the line 3-3 in FIG. 2;

FIG. 4 shows a vertical cross-section through an apparatus applied on a cylinder drying machine, a so-called Yankee machine;

FIG. 5 is an enlarged vertical cross section of the lapparatus of FIG. 4; and

FIG. 6 shows in a developed projection aview along the line VI-VI in FIG. 5 of the bottom of the distributing box in the embodiment of the apparatus shown in FIG. 4.

In the drawings 1 designates a distributing box for the supply of a gaseous treating medium-preferably air of suitable condition-against a web-like material 2. The distributing box is provided with a wall 3 facing the web and being parallel to same, which wall is equipped with a great number of apertures 4 with a small diameter. These apertures are, as is evident especially from FIG. 2, uniformly distributed over the entire wall surface 3. The distributing box is connected to one or more means 5 for the supply and conditioning of the treating medium. In the case shown these means consist of a fan 6 which by means of transition piece 7 is connected to said distributing box 1 and a heating element 10 connected to the suction side 8 of the fan by means of a duct 9. 11 designates a hood disposed above the distributing box 1 for the recirculation of the treating medium. 12 designates openings in the wall surface 3 of the distributing box for the discharge of the medium being supplied to the web. Said openings are, as is evident from FIG. 2, in the same manner uniformlydistributed over the entire wall surface but are less in number and of a greater diameter than the supply apertures 4. Said openings communicate with the suction side 8 of the supply means'or with the atmosphere through an opening 20 by means of pipes 13 passing through the distributing box 1. Instead of employing the opening 20, the entire hood 11 may be removed When discharging to the atmosphere.

For the adjustment of the medium supply in order to obtain a possibility for variation of the treating efiect on different parts of the web in the lateral direction of same the apparatus may suitably be provided with means for dividing the medium current into a number of mutually adjustable currents. In the case shown in FIG. 1 said means consists of a partitioning wall 14 dividing the distributing box into two channels 15 and 16 respectively. Regulating dampers 17 and 18 respectively are arranged between the supply means 6 and said channels. Such a division of the distributing box into channels may be made 3 either merely in front of the supply means or along the whole length of the distributing box.

FIGS. 4 to 6 inclusive show an embodiment of the invention'applied to a Yankee dryer. In this embodiment, a distributing box 21 is provided with a wall 23 acing the Web 22 and having a .plurality of small-diameter apertures 24. The medium is supplied to the distributing box 21 by a Propeller fan 25 which has heating elements 3G connected to its suction side. A hood 31 is disposed above the distributing box 21 for recirculating Vthe gaseous me; dium and pipes 33 Vpass through the distributng box to connect the hood 31 With the uniformly distributed discharge openings 32 in the wall 23. An opening 40 is provided to afiord discharge of the medium to the atmosphere, or the hood 31 may be removed entirely. Deflectors may be provided at 41 and 42 opposite the fan 26 and regulating dampers 37 and 38 are provided for adjusting the flow on different portions of the Web. t

The manner for the supply and discharge 'of the treating medium and-With respect to the apparatus-.the design ofV the dstributing box is fundamental for the invention While other details such as fans, heating elements etc. may be varied Within the scope of the invention as the case may be both With respeect to the design and the position.

What we claim is:

1. VApparatus for treatment of a Web by means of a gaseous treating medium consisting of a distributing box for the gaseous treating medium having a wall facing the web and parallel to the same and a partition parallel to the Web-'facing wall and Vhaving a terminal portion dividing said'wall into separate areas, and at least one means for conditioning and supplying the treating medium to said box including regulatng means independently adjustablet acterized in that the Wall of the distributing box facing thel Web is provided with -a great number of supply apertures for discharging the treating medium against the web, having a small diameter and being uniformiy distributed over the wall area, said wall furthermore being provided with exhaust openings disposed among said supply apertures and in the same manner uniformly distributed over the Wall area so that said supply apertures surround each exhaust opening, said openings being in number less than but having a greater diameter than said supply apertures, tubes passing through said distributing boxy respectively connected at one end to said openings, and a hood connected to the other ends of said tubes, thereby eifecting communication between said openings and the suction side of said means for supplying the treating medium.

2. Apparatus according to claim 1 Wherein said separate areas of the web-facing Wall are disposed respectively adjacent to and remote from said means for conditioning and supplying the treating medium.

References Cited in the file of this patent) UNITED STATES PATENTS France Dec. 12, 1955 

